Costco is a fantastic retailer who has a second to none return policy. Product pricing is usually hard to beat except on delivered goods there is a slightly higher price that varies as shipping is free, so the price reflects that. Monthly and other frequent sales are also great! The first day or two of a new sale the store is usually extra busy! I prefer shopping in store when I can however I have used the Costco.ca site many times and delivery is usually prompt and affordable.
There are a lot of items on the website that are simply not stocked in the warehouse and the warranties are generous and extended warranties on electronics and appliances are reasonable when needed,